intracloud lightning

Intracloud lightning is a type of lightning discharge that occurs within a single thunderstorm cloud. It is the most common form of lightning, accounting for roughly two-thirds of all lightning flashes.1

This electrical activity arises from the separation of positive and negative charges within the cloud. Typically, negative charges accumulate at lower altitudes, while positive charges are found at higher altitudes. This charge separation is thought to be caused by collisions between different-sized ice particles, such as graupel and ice crystals, within the cloud's updrafts and downdrafts.12

When the electrical potential difference becomes sufficiently large, a discharge occurs. Intracloud lightning typically begins with a leader that propagates between regions of opposite charge. This is followed by a luminous discharge that transfers charge, similar in magnitude to a ground discharge, but with slower propagation speeds and lower peak currents.1